Semiconductor device and method of manufacturing the same

ABSTRACT

A semiconductor device includes a substrate, a semiconductor element disposed on the substrate, and a heat conductive member composed of a solder material. The heat conductive member covers the semiconductor element, and is connected to a connection pad formed on the substrate. A heat radiator is disposed on the heat conductive member. The heat conductive member thermally connecting the semiconductor element to the heat radiator reduces the risk that electromagnetic noise may be emitted from or may be incident on the semiconductor element.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority of theprior Japanese Patent Application No. 2011-068176, filed on Mar. 25,2011, the entire contents of which are incorporated herein by reference.

FIELD

The embodiments discussed herein are related to semiconductor devicesand methods of manufacturing the same.

BACKGROUND

In some technologies, heat generated at semiconductor elements includedin semiconductor devices is dissipated using heat radiators such as heatspreaders, heat sinks, and radiator caps thermally connected to thesemiconductor elements with heat conductive members interposedtherebetween. In view of reducing the risk of malfunction of thesemiconductor elements caused by electromagnetic noise, shieldingmembers may be disposed on the peripheries of the semiconductorelements, or the heat radiators such as heat sinks and radiator caps maybe used as the shielding members (see, for example, Japanese Laid-openPatent Publication Nos. 2009-105366, 2002-158317, and 2005-026373 andJapanese National Publication of International Patent Application No.2006-510235).

The shielding members or the heat radiators used as the shieldingmembers are disposed on the semiconductor elements or disposed so as tocover the semiconductor elements, and are electrically connected toconductive portions, for example, portions at a ground (GND) potential,of substrates on which the semiconductor elements are mounted. However,fabrication of these shielding members or heat radiators may lead to anincrease in the number of parts of the semiconductor devices orrelatively significant design changes, and may result in increases in,for example, cost and the number of assembling steps.

SUMMARY

According to an aspect of the present invention, a semiconductor deviceincludes a substrate; an electrode portion disposed on the substrate; asemiconductor element disposed on the substrate; a heat conductivemember composed of a solder material, the heat conductive membercovering the semiconductor element and being connected to the electrodeportion; and a heat radiator disposed on the heat conductive member.

The object and advantages of the invention will be realized and attainedby means of the elements and combinations particularly pointed out inthe claims.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and arenot restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example semiconductor device according to a firstembodiment;

FIG. 2 is a schematic plan view of a principal part of the examplesemiconductor device according to the first embodiment;

FIG. 3 is a schematic plan view from above a recessed portion of a heatradiator;

FIGS. 4A and 4B illustrate an example substrate preparation stepaccording to the first embodiment;

FIGS. 5A and 5B illustrate an example semiconductor-element mountingstep according to the first embodiment;

FIGS. 6A and 6B illustrate an example underfill-resin application stepaccording to the first embodiment;

FIG. 7 illustrates an example sealing-member placement step according tothe first embodiment;

FIGS. 8A and 8B illustrate an example sealing step according to thefirst embodiment;

FIGS. 9A and 9B illustrate an example ball attachment step according tothe first embodiment;

FIGS. 10A and 10B illustrate an example heat conductive member;

FIG. 11 illustrates an example semiconductor device of another form;

FIGS. 12A and 12B illustrate an example of how the semiconductor deviceof the other form is formed;

FIGS. 13A and 13B illustrate another example of how the semiconductordevice of the other form is formed;

FIGS. 14A and 14B illustrate an example semiconductor device accordingto a second embodiment;

FIGS. 15A and 15B illustrate an example semiconductor device accordingto a third embodiment;

FIGS. 16A and 16B illustrate an example substrate preparation stepaccording to the third embodiment;

FIGS. 17A and 17B illustrate an example semiconductor-element mountingstep according to the third embodiment;

FIG. 18 illustrates an example sealing-member placement step accordingto the third embodiment;

FIGS. 19A and 19B illustrate an example sealing step according to thethird embodiment;

FIGS. 20A and 20B illustrate an example underfill-resin application stepaccording to the third embodiment;

FIGS. 21A and 21B illustrate another example semiconductor-deviceforming step;

FIGS. 22A and 22B illustrate an example semiconductor device accordingto a fourth embodiment;

FIGS. 23A and 23B illustrate a first modification of the semiconductordevice according to the fourth embodiment;

FIGS. 24A and 24B illustrate a second modification of the semiconductordevice according to the fourth embodiment;

FIGS. 25A and 25B illustrate another example semiconductor-deviceforming step;

FIGS. 26A and 26B illustrate semiconductor devices of other forms;

FIGS. 27A and 27B illustrate an example semiconductor device accordingto a fifth embodiment;

FIGS. 28A and 28B illustrate an example semiconductor device accordingto a sixth embodiment;

FIG. 29 is a first graph illustrating adhesiveness of a heat conductivemember;

FIGS. 30A and 30B are second graphs illustrating the adhesiveness of theheat conductive member; and

FIGS. 31A and 31B are third graphs illustrating the adhesiveness of theheat conductive member.

DESCRIPTION OF EMBODIMENTS

Several embodiments will be described below with reference to theaccompanying drawings, wherein like reference numerals refer to likeelements throughout.

(a) First Embodiment

A first embodiment will now be described. FIG. 1 illustrates an examplesemiconductor device according to the first embodiment.

A semiconductor device 10A according to the first embodiment includes asubstrate (wiring board) 11 and a semiconductor element (semiconductorchip) 12 disposed on the substrate 11.

The substrate 11 has electrode portions (substrate electrode pads) 11 adisposed on a surface opposing the semiconductor element 12. Thesubstrate electrode pads 11 a are electrically connected by vias 11 d toan internal wiring line 11 c at a ground (GND) potential and signallines (not illustrated) disposed inside the substrate 11.

The semiconductor element 12 has electrode portions (chip electrodepads) 12 a disposed on a surface opposing the substrate 11 at positionscorresponding to the substrate electrode pads 11 a. The semiconductorelement 12 is mounted (flip-chip mounted) on the substrate 11 by thechip electrode pads 12 a connected to the opposing substrate electrodepads 11 a with bumps 13 interposed therebetween.

An underfill resin 14 is disposed between the substrate 11 and thesemiconductor element 12 and around the outer circumference of thesemiconductor element 12.

The semiconductor device 10A includes a heat conductive member 15covering the semiconductor element 12 mounted on the substrate 11. Thisheat conductive member 15 may be composed of a thermally andelectrically conductive material having high workability.

For example, the heat conductive member 15 may be composed of a soldermaterial.

The upper surface of the semiconductor element 12 and the heatconductive member 15 are joined to each other by a bonding layer 16 ainterposed therebetween. A metallized layer may be used as the bondinglayer 16 a. The metallized layer may be, for example, a layeredstructure (Ti/Au) including a titanium (Ti) layer and a gold (Au) layer.In addition, the metallized layer may be, for example, a layeredstructure (Ti/Ni—V/Au) including a Ti layer, a nickel-vanadium (Ni—V)layer, and a Au layer. These layered structures may be formed by, forexample, sputtering. Moreover, a Ni-based plated layer may be used asthe metallized layer serving as the bonding layer 16 a as long as themetallized layer is connectable to the heat conductive member 15.

The heat conductive member 15 covers the upper surface of thesemiconductor element 12, extends along the side surfaces of thesemiconductor element 12 and the side surfaces (fillet portions) of theunderfill resin 14, and is connected to an electrode portion (connectionpad) 11 b disposed on the substrate 11.

FIG. 2 is a schematic plan view of a principal part of the examplesemiconductor device according to the first embodiment. In FIG. 2, theheat conductive member 15 is not illustrated.

In the semiconductor device 10A, the semiconductor element 12 having thebonding layer 16 a disposed on the upper surface thereof is mounted onthe substrate 11, and the underfill resin 14 is disposed between thesubstrate 11 and the semiconductor element 12 and around the outercircumference of the semiconductor element 12. The connection pad 11 bis disposed on the substrate 11 so as to surround an area in which thesemiconductor element 12 is mounted. The heat conductive member 15covers the semiconductor element 12 mounted in the area inside theconnection pad 11 b, and is connected to the connection pad 11 b.

As illustrated in FIG. 1, the connection pad 11 b connected to the heatconductive member 15 is electrically connected by the vias 11 d to theinternal wiring line 11 c at the GND potential disposed inside thesubstrate 11. The heat conductive member 15 connected to the connectionpad 11 b as above functions as a shielding member that reduces the riskof emission of electromagnetic noise from the semiconductor element 12or incidence of electromagnetic noise from the outside to thesemiconductor element 12.

A heat radiator 17 is disposed on a surface, of the substrate 11, onwhich the semiconductor element 12 is mounted. FIG. 3 is a schematicplan view from above a recessed portion 17 a of the heat radiator 17.

The heat radiator 17 has the recessed portion 17 a illustrated in FIGS.1 and 3. The heat radiator 17 is disposed on the substrate 11 such thatthe semiconductor element 12 and the heat conductive member 15 thatcovers the semiconductor element 12 are accommodated in the recessedportion 17 a. A bonding layer 16 b is disposed in the recessed portion17 a of the heat radiator 17. As illustrated in FIG. 1, the heatradiator 17 is joined to the heat conductive member 15 by the bondinglayer 16 b, and is bonded to the substrate 11 by an adhesive 18.

The heat radiator 17 may be composed of a material having a high thermalconductivity and an excellent heat dissipation characteristic. Forexample, the heat radiator 17 may be composed of copper (Cu), aluminum(Al), aluminum silicon carbide (AlSiC), aluminum carbon (AlC), orsilicon rubber.

The bonding layer 16 b disposed in the recessed portion 17 a of the heatradiator 17 may be a metallized layer. The metallized layer may be, forexample, a layered structure (Ni/Au) including a Ni layer and a Aulayer. The Ni/Au layered structure may be formed by, for example,plating. Moreover, a tin (Sn) layer, a silver (Ag) layer, or a Ni layerformed by, for example, plating may be used as the metallized layerserving as the bonding layer 16 b as long as the metallized layer isconnectable to the heat conductive member 15. Furthermore, a Cu layer oran Al layer, for example, may also be used as the metallized layerdepending on the material of the heat radiator 17.

Electrode portions (ball pads) 11 e are disposed on a surface of thesubstrate 11 opposite to that on which the semiconductor element 12 ismounted. The ball pads 11 e are electrically connected by the vias 11 dto the internal wiring line 11 c at the GND potential and the signallines (not illustrated). Solder balls 19 are attached to the ball pads11 e. The semiconductor device 10A may be mounted on another substrate(wiring board) such as a mother board and an interposer using the solderballs 19 and the ball pads 11 e.

The conductive portions including the substrate electrode pads 11 a, theconnection pad 11 b, the internal wiring line 11 c, the vias 11 d, theball pads 11 e, and the signal lines (not illustrated) provided for thesubstrate 11 may be composed of conductive materials such as Cu and Al.

The semiconductor device 10A having the above-described structureefficiently transfers heat generated at the semiconductor element 12 tothe heat radiator 17 through the heat conductive member 15. This reducesthe risk of overheating of the semiconductor element 12, and therebyreduces the risk of malfunction or breakage of the semiconductor element12 caused by the overheating.

In addition, the heat conductive member 15 that thermally connects thesemiconductor element 12 to the heat radiator 17 covers thesemiconductor element 12, and is connected to the connection pad 11 b atthe GND potential in the semiconductor device 10A. As a result, the heatconductive member 15 functions as a shielding member, and effectivelyreduces the risk that electromagnetic noise may be emitted from or maybe incident on the semiconductor element 12, thereby reducing the riskof malfunction of the semiconductor element 12.

Furthermore, significant design or structural changes in the substrate11 are not necessary since the heat conductive member 15 functioning asthe shielding member is at the GND potential. This allows thesemiconductor device 10A having the functions of heat dissipation andelectromagnetic shielding to be manufactured with the least increase incost.

Next, a method of forming (assembling) the semiconductor device 10A willbe described.

FIGS. 4A and 4B illustrate an example substrate preparation stepaccording to the first embodiment. FIG. 4A is a schematic cross-sectiontaken along line L1-L1 in FIG. 4B, and FIG. 4B is a schematic plan view.

On the formation of the semiconductor device 10A, the substrate 11 asillustrated in FIGS. 4A and 4B is prepared first. The substrate 11 hasthe internal wiring line 11 c at the GND potential and the vias 11 dconnected to the internal wiring line 11 c disposed inside an insulatingportion 11 f.

The substrate 11 has the substrate electrode pads 11 a and theconnection pad 11 b on one of the main surfaces thereof. The substrateelectrode pads 11 a are disposed in an area in which the semiconductorelement 12 is to be mounted, and the connection pad 11 b surrounds thearea. The substrate 11 has the ball pads 11 e on the other main surface,the solder balls 19 being attachable to the ball pads 11 e.

Herein, signal lines inside the substrate 11 are not illustrated.

The semiconductor element 12 is mounted on this substrate 11.

FIGS. 5A and 5B illustrate an example semiconductor-element mountingstep according to the first embodiment. FIG. 5A is a schematiccross-section taken along line L2-L2 in FIG. 5B, and FIG. 5B is aschematic plan view.

The semiconductor element 12 to be mounted has the chip electrode pads12 a, the bumps 13 attached to the chip electrode pads 12 a, and abonding layer 16 a on a surface opposite to that to which the bumps 13are attached.

The bumps 13 attached to the chip electrode pads 12 a are aligned withthe substrate electrode pads 11 a, and the chip electrode pads 12 a andthe substrate electrode pads 11 a are connected to each other with thebumps 13 interposed therebetween. In this manner, the semiconductorelement 12 is flip-chip mounted on the substrate 11. The semiconductorelement 12 may be mounted on the substrate 11 with, for example, aflip-chip bonder.

After the semiconductor element 12 is mounted on the substrate 11,application of the underfill resin 14 is performed.

FIGS. 6A and 6B illustrate an example underfill-resin application stepaccording to the first embodiment. FIG. 6A is a schematic cross-sectiontaken along line L3-L3 in FIG. 6B, and FIG. 6B is a schematic plan view.

The underfill resin 14 is applied to a space between the substrate 11and the semiconductor element 12 mounted on the substrate 11, and iscured in the space. The underfill resin 14 may also be formed around theouter circumference of the semiconductor element 12. The application ofthe underfill resin 14 firmly connects the substrate 11 and thesemiconductor element 12, and improves the reliability of connectionstherebetween.

Next, the heat conductive member 15, serving as a sealing member thatseals the periphery of the semiconductor element 12, and the heatradiator 17 are disposed on the substrate 11 on which the semiconductorelement 12 is mounted as above.

FIG. 7 illustrates an example sealing-member placement step according tothe first embodiment.

Herein, the heat conductive member 15 covering the semiconductor element12 has, for example, a recessed portion 15 a having a shapecorresponding to the semiconductor element 12 (shape corresponding tothe external shape of the semiconductor element 12) and a connectingportion 15 b to be connected to the connection pad 11 b. The heatconductive member 15 will be described in detail below.

The heat radiator 17 has the recessed portion 17 a capable ofaccommodating the semiconductor element 12 and the heat conductivemember 15, and is provided with the bonding layer 16 b disposed in therecessed portion 17 a at a position where the bonding layer 16 b is tobe joined to the heat conductive member 15.

The heat conductive member 15 is disposed on the semiconductor element12, and the heat radiator 17 is disposed on the heat conductive member15. The adhesive is disposed between the heat radiator 17 and thesubstrate 11. The semiconductor element 12 is then sealed by the heatconductive member 15, the heat radiator 17 provided with the bondinglayer 16 b, and the adhesive 18 disposed as above.

FIGS. 8A and 8B illustrate an example sealing step according to thefirst embodiment. FIG. 8A is a schematic cross-section taken along lineL4-L4 in FIG. 8B, and FIG. 8B is a schematic plan view.

To seal the semiconductor element 12, the heat radiator 17 is pressedtoward the substrate 11 with the heat conductive member 15 interposedbetween the heat radiator 17 and the semiconductor element 12 mounted onthe substrate 11. With this, the heat radiator 17 is bonded to thesubstrate 11 by the adhesive 18, the heat conductive member 15 isconnected to the bonding layers 16 a and 16 b, and the connectingportion 15 b of the heat conductive member 15 is connected to theconnection pad 11 b.

The semiconductor element 12 is covered by the heat conductive member 15by pressing the heat radiator 17 as above. During pressing of the heatradiator 17, the heat conductive member 15 is brought into close contactwith the bonding layers 16 a and 16 b and the connection pad 11 b. Inaddition, in order for the heat conductive member 15 to be brought intoclose contact with the side surfaces of the semiconductor element 12 andthe underfill resin 14, the heat conductive member 15 may be preferablyheated so as to be melted or softened. Pressing of the heat radiator 17and the adhesiveness of the heat conductive member 15 will be describedin detail below.

After the sealing, the solder balls 19 are attached to the substrate 11.

FIGS. 9A and 9B illustrate an example ball attachment step according tothe first embodiment. FIG. 9A is a schematic cross-section taken alongline L5-L5 in FIG. 9B, and FIG. 9B is a schematic plan view from abovethe surface to which the balls are attached.

The solder balls 19 are attached to the ball pads 11 e disposed on thesurface of the substrate 11 opposite to that on which the semiconductorelement 12 is mounted. This completes the formation of the semiconductordevice 10A of the ball grid array (BGA) type. The semiconductor device10A may be of the land grid array (LGA) type that does not have thesolder balls 19 attached thereto (see FIG. 8).

The heat conductive member 15 will now be described in more detail.

The heat conductive member 15 may be composed of a solder material.Materials to be used as the solder material may vary widely in theproperties and the compositions. For example, materials based on indium(In), indium-silver (In—Ag), tin-lead (Sn—Pb), tin-bismuth (Sn—Bi),tin-silver (Sn—Ag), tin-antimony (Sn—Sb), and tin-zinc (Sn—Zn) may beused as the solder material.

The heat conductive member 15 composed of the above-described soldermaterial and having predetermined dimensions and shape, for example, maybe prepared before assembling the semiconductor device 10A.

The dimensions and the shape of the heat conductive member 15 will nowbe described.

FIGS. 10A and 10B illustrate an example heat conductive member. FIG. 10Ais a schematic cross-section of the heat conductive member beforeassembling, and FIG. 10B is a schematic cross-section of thesemiconductor device after assembling.

As illustrated in FIG. 10A, the heat conductive member 15 is formed of atabular body having a predetermined thickness T, and has the recessedportion 15 a having a predetermined plane size S and a height H beforeassembling the semiconductor device 10A. The plane size S and the heightH of the recessed portion 15 a may be set on the basis of the outsidesize Sa and the mounting height Ha of the semiconductor element 12 to bemounted on the substrate 11 as illustrated in FIG. 10B. Herein, themounting height Ha is defined as a height from the substrate electrodepads 11 a (or the connection pad 11 b) to the surface of the bondinglayer 16 a disposed on the semiconductor element 12.

For example, the plane size S of the recessed portion 15 a of the heatconductive member 15 is set to the outside size Sa of the semiconductorelement 12, and the height H of the recessed portion 15 a is set to themounting height Ha. Herein, the semiconductor element 12 has an outsidesize Sa of 20.0 mm×20.0 mm and a mounting height Ha of 0.610 mm (thethickness of the semiconductor element 12 is 0.550 mm and that of thebumps 13 is 0.060 mm), for example. In this case, the heat conductivemember 15 before assembling may have a thickness T of 0.350 mm, and therecessed portion 15 a may have a plane size S of 20.0 mm×20.0 mm and aheight H of 0.610 mm.

The actual mounting height Ha may vary for each semiconductor device 10Ato be assembled. This may result in a difference between the actualmounting height Ha and the height of the recessed portion 15 a of theheat conductive member 15 prepared so as to have predetermineddimensions and shape in advance in each semiconductor device 10A.

When there is such a difference in the height, the height (thickness Ta)of a part of the heat conductive member 15 located between the uppersurface of the semiconductor element 12 and the heat radiator 17 isadjusted by adjusting the pressure (amount of push) to the heat radiator17. This adjustment removes the difference between the height of therecessed portion 15 a before assembling and the actual mounting heightHa.

When the heat radiator 17 is pressed toward the substrate 11, the heatconductive member 15 composed of a solder material may be melted orsoftened by heating. The heat conductive member 15 may also remainsolidified without being heated.

The heat conductive member 15 is preferably composed of a soldermaterial as described above in view of, for example, heattransferability from the semiconductor element 12 to the heat radiator17, workability depending on the form of the semiconductor element 12,and connectivity to the bonding layers 16 a and 16 b and the connectionpad 11 b.

To remove the difference in the height, relationship between themounting height Ha and the amount of push to the heat radiator 17 may bedetermined in advance, and the amount of push of the heat radiator 17may be adjusted on the basis of the actual mounting height Ha. Inaddition, the thickness, the elasticity, or other parameters of theadhesive 18 that bonds the heat radiator 17 to the substrate 11 may beadjusted in advance so as to remove the difference in the height.

Although the heat conductive member 15 herein has the connecting portion15 b that may be brought into surface contact with the connection pad 11b during assembling, the heat conductive member 15 does not necessarilyneed to have the connecting portion 15 b before assembling as long asthe heat conductive member 15 is connected to the connection pad 11 bafter assembling.

The recessed portion 15 a of the heat conductive member 15 having thesize depending on the outside size of the semiconductor element 12 mayreduce the risk of displacement between the heat conductive member 15and the heat radiator 17 during assembling of the semiconductor device10A.

For comparison, FIG. 11 illustrates an example semiconductor device ofanother form, and FIGS. 12A to 13B illustrate examples of how thesemiconductor device of the other form is formed. FIG. 11 is a schematiccross-section. FIG. 12A is a schematic cross-section taken along lineL6-L6 in FIG. 12B, and FIG. 13A is a schematic cross-sections takenalong line L7-L7 in FIG. 13B. FIGS. 12B and 13B are schematic planviews.

The surface of the semiconductor element 12 adjacent to the bondinglayer 16 a is not necessarily flat after the semiconductor element 12 ismounted on the substrate 11. The semiconductor element 12 may warp dueto differences in thermal expansion and thermal shrinkage between thesemiconductor element 12 and the substrate 11. When a tabular heatconductive member 150 as illustrated in FIGS. 12A to 13B is disposed onthe semiconductor element 12 warping as above, the heat conductivemember 150 or the heat radiator 17 may be displaced.

For example, the tabular heat conductive member 150 is disposed betweenthe semiconductor element 12 provided with the bonding layer 16 a andthe heat radiator 17 provided with the bonding layer 16 b, and the heatradiator 17 is bonded to the substrate 11. At this moment, the heatconductive member 150 disposed on the semiconductor element 12 mayrotate about the protruding portion of the warping semiconductor element12, and may be displaced as illustrated in FIGS. 12A and 12B. Inaddition, the heat radiator 17 disposed on the heat conductive member150 may rotate together with the heat conductive member 150, and boththe heat conductive member 150 and the heat radiator 17 may be displacedas illustrated in FIGS. 13A and 13B.

If the heat conductive member 150 is fixed while being displaced, theupper surface of the semiconductor element 12 partially remainsuncovered by the heat conductive member 150, and thereby precludes theformation of a semiconductor device 100 as illustrated in FIG. 11.Portions of the upper surface of the semiconductor element 12 uncoveredby the heat conductive member 150 may cause an increase in thermalresistance to the heat radiator 17, and may prevent heat generated atthe semiconductor element 12 from being sufficiently transferred to andreleased from the heat radiator 17. This may result in overheating ofthe semiconductor element 12, and therefore in malfunction of thesemiconductor element 12. In addition, this may cause a reduction in theyield of the semiconductor device 100.

In contrast, the semiconductor device 10A described above includes theheat conductive member 15 having the recessed portion 15 a, and thedimensions and the shape of the recessed portion 15 a are set on thebasis of the outside size and the mounting height of the semiconductorelement 12 after mounting. With this, each inner side (or inner surface)of the recessed portion 15 a opposes the corresponding outer side (orside surface) of the semiconductor element 12 during assembling, therebyreducing the risk of the rotation of the heat conductive member 15. As aresult, the heat conductive member 15 is accurately positioned on theupper surface of the semiconductor element 12, and covers the uppersurface and the side surfaces of the semiconductor element 12 inaddition to the side surfaces of the underfill resin 14.

In addition, as illustrated in FIGS. 7, 8A, and 8B, the heat conductivemember 15 having the recessed portion 15 a is disposed on thesemiconductor element 12, and the heat radiator 17 is pressed toward thesubstrate 11 while, for example, the heat conductive member 15 isheated. At this moment, connections between the heat conductive member15 and the bonding layer 16 a provided for the semiconductor element 12,between the heat conductive member 15 and the bonding layer 16 bprovided for the heat radiator 17, and between the heat conductivemember 15 and the connection pad 11 b at the GND potential are performedin a single step. In this manner, the semiconductor device 10A, havingthe functions of heat dissipation and electromagnetic shielding, isefficiently assembled.

(b) Second Embodiment

A second embodiment will now be described. FIGS. 14A and 14B illustratean example semiconductor device according to the second embodiment. FIG.14A is a schematic cross-section taken along line L8-L8 in FIG. 14B, andFIG. 14B is a schematic plan view.

A semiconductor device 10B according to the second embodiment differsfrom the semiconductor device 10A according to the first embodiment inthat the semiconductor device 10B includes a small substrate 11 and asmall tabular heat radiator 17.

In the semiconductor device 10B, the heat radiator 17 does not need tohave a structure surrounding the periphery of a semiconductor element 12and to be connected to the substrate 11, that is, a recessed portion 17a unlike the semiconductor device 10A according to the first embodiment.Since this small tabular heat radiator 17 is used, the substrate 11 doesnot need to have an area to which the heat radiator 17 is bonded, and anadhesive 18 used to bond the heat radiator 17 to the substrate 11 isalso not necessary.

The use of the heat radiator 17 and the substrate 11 as illustrated inFIGS. 14A and 14B allows the small semiconductor device 10B, using aheat conductive member 15 thermally connecting the semiconductor element12 to the heat radiator 17 as a shielding member, to be realized.

This semiconductor device 10B may be formed in a manner similar to thatdescribed in the first embodiment.

That is, the semiconductor element 12 provided with a bonding layer 16 ais flip-chip mounted on the small substrate 11 with bumps 13 interposedtherebetween first. Subsequently, an underfill resin 14 is appliedbetween the substrate 11 and the semiconductor element 12. The tabularheat conductive member 15 is then disposed on the semiconductor element12 and the bonding layer 16 a, and the heat radiator 17 provided with abonding layer 16 b is disposed on the heat conductive member 15. Theheat radiator 17 is pressed toward the substrate 11 while, for example,the heat conductive member 15 is heated. At this moment, connectionsbetween the heat conductive member 15 and the bonding layer 16 a,between the heat conductive member 15 and the bonding layer 16 b, andbetween the heat conductive member 15 and a connection pad 11 b areperformed in a single step. In this manner, the semiconductor device 10Bis efficiently formed.

Although the semiconductor device 10B of the BGA type having solderballs 19 attached to ball pads 11 e is illustrated in FIGS. 14A and 14B,the semiconductor device 10B may be of the LGA type that does not havethe solder balls 19 attached thereto.

(c) Third Embodiment

A third embodiment will now be described. FIGS. 15A and 15B illustratean example semiconductor device according to the third embodiment. FIG.15A is a schematic cross-section taken along line L9-L9 in FIG. 15B, andFIG. 15B is a schematic plan view.

A semiconductor device 10C according to the third embodiment differsfrom the semiconductor device 10B according to the second embodiment inthat the semiconductor device 10C includes a heat conductive member 15having an opening 15 c. The opening 15 c of the heat conductive member15 may be used for application of an underfill resin 14 (describedbelow).

A method of forming the semiconductor device 10C including the heatconductive member 15 having the opening 15 c will now be described.

FIGS. 16A and 16B illustrate an example substrate preparation stepaccording to the third embodiment. FIG. 16A is a schematic cross-sectiontaken along line L10-L10 in FIG. 16B, and FIG. 16B is a schematic planview.

First, a small substrate 11 as illustrated in FIGS. 16A and 16B isprepared. Herein, the substrate 11 has no area to which a heat radiator17 is bonded. The substrate 11 includes substrate electrode pads 11 a, aconnection pad 11 b, an internal wiring line 11 c, vias 11 d, ball pads11 e, conductive portions such as signal lines (not shown), and aninsulating portion 11 f. The internal wiring line 11 c is at a GNDpotential. The substrate electrode pads 11 a are disposed in an area inwhich a semiconductor element 12 is to be mounted, and the connectionpad 11 b surrounds the area.

FIGS. 17A and 17B illustrate an example semiconductor-element mountingstep according to the third embodiment. FIG. 17A is a schematiccross-section taken along line L11-L11 in FIG. 17B, and FIG. 17B is aschematic plan view.

The semiconductor element 12 has chip electrode pads 12 a disposed on asurface thereof and a bonding layer 16 a disposed on a surface oppositeto that on which the chip electrode pads 12 a are disposed. Bumps 13 areattached to the chip electrode pads 12 a, and the semiconductor element12 is flip-chip mounted on the substrate 11.

FIG. 18 illustrates an example sealing-member placement step accordingto the third embodiment.

After the semiconductor element 12 is mounted on the substrate 11, thetabular heat conductive member 15 is disposed on the bonding layer 16 aprovided for the semiconductor element 12, and the heat radiator 17provided with a bonding layer 16 b is disposed on the heat conductivemember 15. Herein, the heat conductive member 15 has a recessed portion15 a, a connecting portion 15 b, and the opening 15 c communicating withthe recessed portion 15 a.

FIGS. 19A and 19B illustrate an example sealing step according to thethird embodiment. FIG. 19A is a schematic cross-section taken along lineL12-L12 in FIG. 19B, and FIG. 19B is a schematic plan view.

After the heat conductive member 15 and the heat radiator 17 aredisposed as above, the heat radiator 17 is pressed toward the substrate11 while, for example, the heat conductive member 15 is heated so thatthe heat conductive member 15 is connected to the bonding layers 16 aand 16 b and the connection pad 11 b. At this moment, the opening 15 cof the heat conductive member 15 communicates with a space between thesemiconductor element 12 and the substrate 11.

Application of the underfill resin 14 is performed after the heatconductive member 15 is connected to the bonding layers 16 a and 16 band the connection pad 11 b.

FIGS. 20A and 20B illustrate an example underfill-resin application stepaccording to the third embodiment. FIG. 20A is a schematic cross-sectiontaken along line L13-L13 in FIG. 20B, and FIG. 20B is a schematic planview.

The underfill resin 14 may be applied using, for example, a dispenser.For example, the underfill resin 14 may be applied from the opening 15 cof the heat conductive member 15 to the space between the semiconductorelement 12 and the substrate 11 using a predetermined needle 50. Duringthe application of the underfill resin 14, the heat conductive member 15covering the semiconductor element 12 and connected to the connectionpad 11 b may function as a dam that prevents the underfill resin 14 fromwetting and spreading to the outside of the area in which thesemiconductor element 12 is mounted.

The size and the shape of the opening 15 c of the heat conductive member15 are not specifically limited as long as the end of the needle 50 isinsertable into the opening 15 c and as long as the heat conductivemember 15 having the opening 15 c has an electromagnetic shieldingeffect on the semiconductor element 12.

A semiconductor device 10C of the LGA type may be formed through theabove-described steps. A semiconductor device 10C of the BGA type may beformed by attaching solder balls 19 to the ball pads 11 e after theapplication of the underfill resin 14.

Through the above-described steps, the heat conductive member 15 reducesthe risk that the underfill resin 14 may wet and spread to the outsideof the area in which the semiconductor element 12 is mounted during theformation of the semiconductor device 10C.

For example, in cases where the underfill resin 14 is applied to thespace between the substrate 11 and the semiconductor element 12 mountedthereon before the heat conductive member 15 is connected to the bondinglayers 16 a and 16 b and the connection pad 11 b, the underfill resin 14may wet and spread as illustrated in FIGS. 21A and 21B.

FIGS. 21A and 21B illustrate another example semiconductor-deviceforming step. FIG. 21A illustrates another example underfill-resinapplication step, and FIG. 21B illustrates another examplesealing-member placement step.

When the underfill resin 14 is applied to the space between thesubstrate 11 and the semiconductor element 12 mounted thereon, theunderfill resin 14 may wet and spread to the outside of the area inwhich the semiconductor element 12 is mounted. The underfill resin 14may wet and spread due to, for example, the viscosity of the underfillresin 14, the amount of underfill resin 14 to be supplied, and thewettability of the substrate 11 by the underfill resin 14. If theunderfill resin 14 wets and spreads, the connection pad 11 b may becovered by the underfill resin 14 as illustrated in FIG. 21A, or theunderfill resin 14 may flow out to, for example, the side surfaces ofthe substrate 11.

In these cases, the heat conductive member 15 may not be connected tothe connection pad 11 b as illustrated in FIG. 21B during placement ofthe heat conductive member 15 and the heat radiator 17. If the heatconductive member 15 is not connected to the substrate 11, the heatconductive member 15 may not be able to exert the electromagneticshielding effect. In addition, if the underfill resin 14 flows out to,for example, the side surfaces of the substrate 11, the finished product(semiconductor device) may have an abnormal external shape or anabnormal appearance.

In contrast, in the semiconductor device 10C, the underfill resin 14 isapplied from the opening 15 c of the heat conductive member 15 to thespace between the semiconductor element 12 and the substrate 11 afterthe heat conductive member 15 having the opening 15 c is connected to,for example, the connection pad 11 b. This reduces the risk that theunderfill resin 14 may flow out to the outside of the area in which thesemiconductor element 12 is mounted, and thus allows poor connectionbetween the heat conductive member 15 and the connection pad 11 b asillustrated in FIGS. 21A and 21B to be avoided. Furthermore, thisreduces the risk that the underfill resin 14 may flow out to, forexample, the side surfaces of the substrate 11, and thus allows anabnormal external shape or an abnormal appearance of the semiconductordevice 10C to be avoided.

(d) Fourth Embodiment

A fourth embodiment will now be described. FIGS. 22A and 22B illustratean example semiconductor device according to the fourth embodiment.

FIGS. 22A and 22B illustrate a method of connecting a tabular heatconductive member 15 to, for example, a connection pad 11 b whileshaping the heat conductive member 15 using a heat radiator 17 providedwith a forming die (recessed portion) 17 b for shaping the heatconductive member 15 during assembling of a semiconductor device 10D,and the resultant semiconductor device 10D.

During assembling of the semiconductor device 10D, a semiconductorelement 12 provided with a bonding layer 16 a is first flip-chip mountedon a substrate 11. Next, the tabular heat conductive member 15, the heatradiator 17 provided with the forming die 17 b for shaping the heatconductive member 15, and an adhesive 18 are disposed on the substrate11 at predetermined positions. Subsequently, the heat radiator 17 ispressed toward the substrate 11 while, for example, the heat conductivemember 15 is heated.

During pressing of the heat radiator 17, the heat conductive member 15disposed between the semiconductor element 12 and the heat radiator 17deforms along the forming die 17 b of the heat radiator 17 while beingsupported by the semiconductor element 12, and covers the semiconductorelement 12 (bonding layer 16 a) and surfaces of an underfill resin 14.At this moment, the heat conductive member 15 is connected to thebonding layer 16 a, a bonding layer 16 b, and the connection pad 11 b,and the heat radiator 17 is bonded to the substrate 11 with the adhesive18 interposed therebetween.

This completes the formation of the semiconductor device 10D of the LGAtype. After this, solder balls as described above may be attached to thesemiconductor device 10D to form the semiconductor device 10D of the BGAtype.

The use of this method eliminates the preparation for the heatconductive member 15 having a shape based on the outside size and themounting height of the semiconductor element 12 before assembling of thesemiconductor device 10D, and reduces the risk of increasing the cost(machining cost) of the heat conductive member 15.

In addition, since the heat radiator 17 is also located adjacent to theperiphery of the semiconductor element 12 in the semiconductor device10D formed using this method, the heat generated at the semiconductorelement 12 is effectively transferred sideward in addition to upward,resulting in an increase in the heat release effect.

Other electronic components including passive parts such as resistorsand capacitors may be mounted on the substrate 11 in addition to thesemiconductor element 12. The method using the heat radiator 17 providedwith the forming die 17 b may also be applicable to cases where suchelectronic components are mounted on the substrate 11.

FIGS. 23A and 23B illustrate a first modification of the semiconductordevice according to the fourth embodiment.

FIGS. 23A and 23B illustrate a method of shaping and connecting thetabular heat conductive member 15 using the substrate 11 on which thesemiconductor element 12 and electronic components 20 are mounted andthe heat radiator 17 provided with the forming die 17 b, and a resultantsemiconductor device 10D1.

The semiconductor device 10D1 may be assembled through the proceduresimilar to that for assembling the semiconductor device 10D.

During pressing of the heat radiator 17, the thickness of the adhesive18 may be adjusted such that the contact between the lower surface ofthe heat radiator 17 and the electronic components 20 is avoided. Inaddition, the shape of the lower surface of the heat radiator 17 may bechanged such that the contact between the heat radiator 17 and theelectronic components 20 is avoided.

FIGS. 24A and 24B illustrate a second modification of the semiconductordevice according to the fourth embodiment.

As in a semiconductor device 10D2 illustrated in FIGS. 24A and 24B, theheat radiator 17 may also have recessed portions 17 c at positionsopposing the electronic components 20 such that predetermined spaces areleft between the heat radiator 17 and the electronic components 20 afterthe heat radiator 17 is bonded to the substrate 11. This allows thecontact between the heat radiator 17 and the electronic components 20 tobe avoided. In addition, these recessed portions 17 c may increase theflexibility in the form (mounting height, type, and the like) of theelectronic components 20 to be mounted on the substrate 11 together withthe semiconductor element 12.

If a heat radiator 17 without the forming die 17 b is used for thetabular heat conductive member 15, the heat conductive member 15 mayspread as illustrated in FIGS. 25A and 25B when the heat conductivemember 15 is connected to the substrate 11 on which the semiconductorelement 12 and the electronic components 20 are mounted.

FIGS. 25A and 25B illustrate another example semiconductor-deviceforming step. FIG. 25A is a schematic cross-section, and FIG. 25B is aschematic plan view.

Herein, the tabular heat conductive member 15 is disposed between theheat radiator 17 provided with a recessed portion 17 a and the substrate11 on which the semiconductor element 12 and the electronic components20 are mounted, and the heat radiator 17 is pressed toward the substrate11. When the heat radiator 17 is pressed while the heat conductivemember 15 is heated, the heat conductive member 15 may be extruded frombetween the heat radiator 17 and the semiconductor element 12 by thepressure, and may spread to the electronic components 20 mounted on theperiphery of the semiconductor element 12 as illustrated in FIGS. 25Aand 25B.

If the heat conductive member 15 spreads as described above and comesinto contact with the electronic components 20, for example, theelectronic components 20 may not function normally. For example, whenthe heat conductive member 15 spreading as described above comes intocontact with chip capacitors serving as the electronic components 20,the chip capacitors may short-circuit.

To avoid failures such as short circuits of the electronic components20, structures as illustrated in FIGS. 26A and 26B may be adopted.

FIGS. 26A and 26B illustrate semiconductor devices of other forms.

For example, the electronic components 20 are disposed outside the heatradiator 17 in the structure illustrated in FIG. 26A. In the structureillustrated in FIG. 26B, the electronic components 20 mounted inside theheat radiator 17 are coated by resins 30.

In the structure as illustrated in FIG. 26A, however, inductance orresistance of wiring lines inside the substrate 11 may increase due tothe long distances between the semiconductor element 12 and theelectronic components 20, and this may result in an increase inswitching noise. In addition, a step of forming the resins 30 isnecessary for the structure illustrated in FIG. 26B, and fabrication ofthe resins 30 may result in an increase in cost.

Meanwhile, the heat radiator 17 provided with the forming die 17 breduces the risk that the heat conductive member 15 may spread to theelectronic components 20 in cases where the electronic components 20 aremounted on the periphery of the semiconductor element 12. This allowsthe contact between the heat conductive member 15 and the electroniccomponents 20 to be avoided, and thus allows failures caused by thecontact to be avoided.

The above-described electronic components 20 may be mounted on thesubstrate 11 of the semiconductor device 10A described in the firstembodiment. Since the semiconductor device 10A includes the heatconductive member 15 having predetermined size and shape, contactbetween the heat conductive member 15 and the electronic components 20and failures caused by the contact may be avoided.

(e) Fifth Embodiment

Next, a fifth embodiment will be described. FIGS. 27A and 27B illustratean example semiconductor device according to the fifth embodiment.

Although the semiconductor devices according to the first and secondembodiments include the underfill resin 14 disposed between thesubstrate 11 and the semiconductor element 12 mounted thereon, such anunderfill resin is not always necessary in the fifth embodiment. As in asemiconductor device 10A1 illustrated in FIG. 27A and a semiconductordevice 10B1 illustrated in FIG. 27B, a semiconductor element 12 may becovered by a heat conductive member 15 without an underfill resin, andthe semiconductor element 12 may be thermally connected to a heatradiator 17 with the heat conductive member 15 interposed therebetween.

In the semiconductor device 10A1 illustrated in FIG. 27A and thesemiconductor device 10B1 in FIG. 27B, the semiconductor element 12 iscovered by the heat conductive member 15, and the heat conductive member15 is connected to a connection pad 11 b and a bonding layer 16 a. Thatis, the heat conductive member 15 reinforces the connection between thesemiconductor element 12 and a substrate 11 via bumps 13.

Therefore, for example, even if differences in thermal expansion andthermal shrinkage between the semiconductor element 12 and the substrate11 cause a warp of the semiconductor element 12 during heating andcooling performed after the semiconductor element 12 is mounted, theheat conductive member 15 reinforces the connection between thesemiconductor element 12 and the substrate 11, and ensures a certainreliability of connections. Even if an impact is given to thesemiconductor devices 10A1 and 10B1 from the outside, the heatconductive member 15 similarly ensures a certain reliability ofconnections.

The material cost of the underfill resin 14 and the step of forming theunderfill resin 14 are unnecessary for the semiconductor devices 10A1and 10B1.

The semiconductor devices 10A1 and 10B1, having the same structures asthe semiconductor devices 10A and 10B, respectively, except that theunderfill resin 14 is omitted therefrom have been illustrated asexamples. Similarly, structures obtained by omitting the underfill resin14 from the semiconductor devices 10D, 10D1, and 10D2 described in thefourth embodiment may also be adopted.

(f) Sixth Embodiment

A sixth embodiment will now be described. FIGS. 28A and 28B illustratean example semiconductor device according to the sixth embodiment.

In the fourth embodiment, the tabular heat conductive member 15 isconnected to the bonding layers 16 a and 16 b and the connection pad 11b so as to cover the semiconductor element 12 while being shaped by theheat radiator 17 provided with the forming die 17 b. Instead of thetabular heat conductive member 15, a heat conductive member 15 in pasteform as illustrated in FIGS. 28A and 28B may be used.

In this case, the heat conductive member 15 in paste form is disposed ona bonding layer 16 a of a semiconductor element 12 mounted on asubstrate 11, and a heat radiator 17, provided with a forming die 17 band a bonding layer 16 b, and an adhesive 18 are disposed atpredetermined positions. The heat radiator 17 is pressed toward thesubstrate 11 so that the heat conductive member 15 deforms along theforming die 17 b to cover the semiconductor element 12 (bonding layer 16a) and surfaces of an underfill resin 14. The heat conductive member 15is connected to the bonding layers 16 a and 16 b and the connection pad11 b, and the heat radiator 17 is bonded to the substrate 11 by theadhesive 18.

This completes the formation of the semiconductor device 10D of the LGAtype. After this, solder balls as described above may be attached to thesemiconductor device 10D to form the semiconductor device 10D of the BGAtype.

The use of the above-described method produces effects similar to thosedescribed in the fourth embodiment. Furthermore, the use of the heatconductive member 15 in paste form may reduce the material and machiningcost compared with the case where the tabular heat conductive member 15or 150 is used.

The heat conductive member 15 in paste form may also be used whenelectronic components 20 as described in the fourth embodiment aremounted on the substrate 11. In this case, the heat radiator 17 may haverecessed portions 17 c at positions opposing the electronic components20.

Next, adhesiveness between the heat conductive member 15 and thesemiconductor element 12 and between the heat conductive member 15 andthe underfill resin 14 will be described with reference to FIGS. 29 to31B.

As illustrated in FIG. 29, an uneven portion 12 b may exist on the rearsurface (surface opposite to that to which bumps 13 are attached) of thesemiconductor element 12. This uneven portion 12 b is formed byback-grinding of a semiconductor substrate performed during forming ofthe semiconductor element 12. Even when the bonding layer 16 a is formedon the surface having the uneven portion 12 b, an uneven portion 16 aamay remain on a side of the semiconductor element 12 adjacent to therear surface. In addition, the underfill resin 14 includes filletportions 14 a at side ends of the semiconductor element 12, and theheight of the fillet portions 14 a may vary (high fillet portions 14 aaor low fillet portions 14 ab) depending on the amount of the underfillresin 14 to be supplied.

The heat conductive member 15 is disposed so as to cover the bondinglayer 16 a on the semiconductor element 12 and the underfill resin 14,the bonding layer 16 a potentially having the uneven portion 16 aa andthe underfill resin 14 having the fillet portions 14 a whose shapepotentially varying. The heat conductive member 15 is preferably broughtinto close contact with the surface of the bonding layer 16 a, the sidesurfaces of the semiconductor element 12, and the surfaces of theunderfill resin 14 such that the least gaps are left between thesecomponents in view of efficiency of heat transfer from the semiconductorelement 12 to the heat radiator 17.

In this regard, the heat radiator 17 is disposed on the semiconductorelement 12 provided with the bonding layer 16 a with the heat conductivemember 15 interposed therebetween, and the heat radiator 17 is pressedtoward the substrate 11 on which the semiconductor element 12 is mountedduring assembling in the first to sixth embodiments. This reduces therisk that gaps may be left between the heat conductive member 15 and thesemiconductor element 12 provided with the bonding layer 16 a andbetween the heat conductive member 15 and the underfill resin 14.

For example, FIGS. 30A and 30B illustrate connection of the heatconductive member 15 to the connection pad 11 b and the like while theheat conductive member 15 is being shaped by the heat radiator 17provided with the forming die 17 b.

In this case, as illustrated in FIG. 30A, gaps 40 are left between theheat conductive member 15 and the uneven portion 16 aa of the bondinglayer 16 a, between the heat conductive member 15 and the side surfacesof the semiconductor element 12, and between the heat conductive member15 and the underfill resin 14 during pressing of the heat radiator 17.However, the heat conductive member 15 deforms along the surface of theuneven portion 16 aa of the bonding layer 16 a, the side surfaces of thesemiconductor element 12, and the surfaces of the fillet portions 14 aof the underfill resin 14 as illustrated in FIG. 30B by further pressingthe heat radiator 17. In this manner, the heat conductive member 15 isbrought into close contact with the surfaces of the bonding layer 16 a,the semiconductor element 12, and the underfill resin 14.

To do this, the thickness of the heat conductive member 15 to be usedand the pressure (load) to the heat radiator 17 necessary for the closecontact may be determined in advance.

Since the heat conductive member 15 melted by heating and the heatconductive member 15 in paste form are fluid, the heat conductive member15 may flow along and be brought into close contact with the surfaces ofthe bonding layer 16 a, the semiconductor element 12, and the underfillresin 14.

At this moment, however, as illustrated in FIG. 31A, air gaps (voids) 41may be formed between the heat conductive member 15 and the surfaces ofthe bonding layer 16 a, the semiconductor element 12, and the underfillresin 14. In this case, the air gaps 41 may be removed or reduced asillustrated in FIG. 31B by applying pressure to the heat conductivemember 15 while heating the heat conductive member 15 using a pressureoven and the like such that the air gaps 41 are crushed and then bycooling and hardening the heat conductive member 15. Alternatively, theair gaps 41 may be removed or reduced as illustrated in FIG. 31B byheating the heat conductive member 15 such that the heat conductivemember 15 is softened or melted, by drawing a vacuum in this state, andthen by cooling and hardening the heat conductive member 15.

In this manner, placing the heat conductive member 15 between the heatradiator 17 and the semiconductor element 12 on the substrate 11 andpressing the heat radiator 17 toward the substrate 11 while heating asneeded may increase the adhesiveness between the heat conductive member15 and the bonding layer 16 a, between the heat conductive member 15 andthe semiconductor element 12, and between the heat conductive member 15and the underfill resin 14. This allows the heat generated at thesemiconductor element 12 to be efficiently transferred to the heatradiator 17 via the heat conductive member 15, and thereby effectivelyreduces the risk of malfunction or breakage of the semiconductor element12 caused by overheating.

Although the adhesiveness of the heat conductive member 15 in caseswhere the heat radiator 17 has the forming die 17 b has been describedwith reference to FIGS. 30A to 31B, certain adhesiveness of theconductive member 15 may also be obtained in cases where the heatradiator 17 has the recessed portion 17 a or where the heat radiator 17is tabular. For example, pressing the heat conductive member 15 providedwith the recessed portion 15 a having appropriately set size and shapeusing the heat radiator 17 provided with the recessed portion 17 a orusing the tabular heat radiator 17 ensures certain adhesiveness betweenthe heat conductive member 15 and the bonding layer 16 a, between theheat conductive member 15 and the semiconductor element 12, and betweenthe heat conductive member 15 and the underfill resin 14.

In the first to sixth embodiments, the semiconductor element isthermally connected to the heat radiator with the heat conductive memberinterposed therebetween, and the heat conductive member is connected tothe electrode portion, at the GND potential, of the substrate whilecovering the semiconductor element. This allows the heat generated atthe semiconductor element to be efficiently transferred to the heatradiator via the heat conductive member while the periphery of thesemiconductor element is electromagnetically shielded by the heatconductive member. The heat conductive member covering the semiconductorelement and connected to the predetermined electrode portion of thesubstrate may be formed by pressing the heat radiator toward thesubstrate without increasing the number of parts or the number ofprocessing steps. This leads to a semiconductor device having functionsof heat dissipation and electromagnetic shielding without the risk ofincreasing the cost. This also leads to an increase in efficiency ofmanufacturing the semiconductor device.

All examples and conditional language recited herein are intended forpedagogical purposes to aid the reader in understanding the inventionand the concepts contributed by the inventor to furthering the art, andare to be construed as being without limitation to such specificallyrecited examples and conditions, nor does the organization of suchexamples in the specification relate to a showing of the superiority andinferiority of the invention. Although the embodiments of the presentinvention have been described in detail, it should be understood thatvarious changes, substitutions, and alterations could be made heretowithout departing from the spirit and scope of the invention.

What is claimed is:
 1. A semiconductor device comprising: a substrate;an electrode portion disposed over the substrate and having an openingregion; a semiconductor element disposed in the opening region over thesubstrate; a heat conductive member composed of a solder material andcovering the semiconductor element, the heat conductive member which hasa series of side walls surrounding the semiconductor element along theelectrode portion and being connected to the electrode portion; and aheat radiator disposed over the heat conductive member; wherein the sidewalls of the heat conductive member which are opposite to adjacent sidesurfaces of the semiconductor element come in contact with each other.2. The semiconductor device according to claim 1, wherein the heatconductive member is disposed along an upper surface and the sidesurfaces of the semiconductor element.
 3. The semiconductor deviceaccording to claim 1, wherein the electrode portion is at a groundpotential.
 4. The semiconductor device according to claim 1, furthercomprising: a resin layer disposed between the substrate and thesemiconductor element.
 5. The semiconductor device according to claim 1,further comprising: a resin layer disposed between the substrate and thesemiconductor element, wherein the heat conductive member has an openingthat communicates with the resin layer.
 6. The semiconductor deviceaccording to claim 1, wherein the heat radiator has a recessed portionthat accommodates the heat conductive member, and the heat conductivemember is disposed along an inner surface of the recessed portion. 7.The semiconductor device according to claim 1, further comprising: afirst bonding layer disposed between an upper surface of thesemiconductor element and the heat conductive member; and a secondbonding layer disposed between an upper surface of the heat conductivemember and the heat radiator.
 8. The semiconductor device according toclaim 1, wherein a part of the side walls of the heat conductive membercontacts with a side surface of the semiconductor element.
 9. Thesemiconductor device according to claim 4, wherein a part of the sidewalls of the heat conductive member contacts with a side surface of theresin layer.
 10. The semiconductor device according to claim 1, whereinthe heat radiator is a tabular member, and outer surfaces of the sidewalls of the heat conductive member are exposed.
 11. The semiconductordevice according to claim 6, wherein the inner surface includes a bottomsurface and side surfaces of the recessed portion of the heat radiator,the inner surface is covered with a third bonding layer, and the thirdbonding layer contacts with an upper surface of the heat conductivemember and the outer surfaces of the side walls of the heat conductivemember.
 12. A semiconductor device comprising: a substrate; an electrodeportion disposed over the substrate; a semiconductor element disposedover the substrate; a heat conductive member composed of a soldermaterial, the heat conductive member covering the semiconductor elementand being connected to the electrode portion; and a heat radiatordisposed over the heat conductive member; wherein a part of side wallsof the heat conductive member contacts with a side surface of thesemiconductor element.
 13. A semiconductor device according to claim 12,wherein the electrode portion surrounds the semiconductor element.